Segmenting ring sizes

[David DiOrio]

I everyone I have been turning for a long time now and wanted to get into segmenting. I made the wedgie sled and can make rings. Now my question is this, if I want to make a 10 inch diameter bowl, the last ring will have a 10 diameter or so. How do I know how much smaller to make each ring under it, if that ring has a 10” diam, the does the one under it have. 9.75? The numbers are used as an example, just trying to figure out how to step up or down with regards to ring diameter. Hope I explained it ok? Thanks everyone for any input.

[John K Jordan]

I everyone I have been turning for a long time now and wanted to get into segmenting. I made the wedgie sled and can make rings. Now my question is this, if I want to make a 10 inch diameter bowl, the last ring will have a 10 diameter or so. How do I know how much smaller to make each ring under it, if that ring has a 10” diam, the does the one under it have. 9.75? The numbers are used as an example, just trying to figure out how to step up or down with regards to ring diameter. Hope I explained it ok? Thanks everyone for any input.

David,

The diameter and width of each layer depends on the shape you want. I would approach this like I do many turnings such as bowls, lidded boxes, Beads of Courage boxes, etc.

I first make a simple sketch of what I wanted the bowl to look like from the side view. (I keep a notebook just for sketching ideas.) Then I make a full-sized drawing of the bowl in cross-section to show the wall thickness. If the piece is too large for a single piece of paper I might make it 1/2 size. I draw horizontal lines for each layer, figure out how wide to make each ring, and measure the diameters directly from the drawing.

This is the way I make things from layers of rings of solid wood but it works the same for segmented rings. By sketching and planning in advance I know the rings are wide enough for the desired wall thickness but not too wide which would take more time effort on the lathe (and could waste a lot of wood!)

You might be interested in some software that makes this easy, Segment Pro. You can draw a profile of one edge and the software will show you how it will look then give you a list of the sizes of each ring, the amount of wood needed, and even the angles for each cut.
http://woodturnerpro.com/software/overview.htm
Their web site used to have pictures of some of the working screens but I don't see them now. Perhaps contact them and ask I think you can download and try the software before buying.

I see there are videos on Vimeo, for example: https://vimeo.com/206785859 Search for others.

A friend of mine uses this software a lot. I bought a copy but I don't have it installed on this laptop yet.

JKJ

[John Brown]

David, Do a search for " segment ring calculator " on the web, you will get several sites to chose from depending on what you want to make, you can take your choice. That is how I found a ring calculator for Christmas ornaments I make.

[Allan Ferguson]

Graphe paper 1/4", draw 1/2 right or left side profile , mark out the rings that allow you the wall thickness you want. Visit segmented wood turners.org

[Grant Wilkinson]

Along with the good advice you've received so far, I suggest that you look on dennyedwards.com. Denny goes great videos on how he does exactly what you are looking for.

[George Troy Hurlburt]

David, welcome to the world of segmentation. I use drawing software like Serif Draw Plus 8 to make my plans, 1/4" squares works also. Here is the bases of all segmented work. This formula here:
Diameter x 3.1416 divide by number of pieces in a ring you want. Numbers are tip to tip. All segments in a ring must equal 360 deg. when you make your cuts. For best results check your wood stock. Your rips must be flat and all edges squares. Besides your table saw you can use a miter saw, or bandsaw. I have a sanding jig(disc sander) I use for super accurate wedges. Curt Theobald showed me how. The how to's go on and on. Posting a drawing of a couple of vases. I also posted other drawings last fall.
Valentine Box 81148.jpg

[Don Jarvie]

Look a few posts down in this forum for Greg Tarrent and he has a program for this. I haven’t tried it but it looks pretty good.

if you use 15 degree cuts for 12 segments per ring the face width should be about 2 to 2 1/4 inches per. To make the ring smaller decrease the size of the face width.

[Robert Hayward]

Segment Pro will do exactly what you are looking for. At a price though, it is for sale software.